This proposal describes a plan to develop stereoselective organic synthetic methods using the reactions of epoxides with enolates. The diastereoselectivity of epoxide reactions with enolates was recently demonstrated by this research group, and the full development of this chemistry is proposed. Methods are suggested to achieve enantioselective reactions via the enolate/epoxide chemistry. Also, the advent of the Sharpless epoxidation makes a limitless number of optically active epoxides available for use in natural and medicinal product synthesis via these routes: the development of this carbon-carbon bond formation chemistry would be of obvious benefit in the synthesis of chiral natural and medicinal products. As an application of the synthetic methods described, the synthesis of the natural products rubrynolide and rubrenolide is planned. These compounds, isolated from the bark of Brazilian trees, are known to have physiological activity, although they have not been fully evaluated for medicinal value. Other related natural products can be made by this epoxide/enolate chemistry. The synthesis of alpha-methylene gamma-lactones appears to be quite possible by the chemistry described herein. There are over 900 varieties of natural products containing this structural feature, many of which have substantial biological activities. Some are allergenic agents, others are cytotoxic and antitumor agents, and others are regulators of plant growth or prossess antimitotic activity.